FUNCTION: [Summary is not available for the mouse gene. This summary is for the human ortholog.] This gene encodes a multidomain serine protease inhibitor that contains 15 potential inhibitory domains. The encoded preproprotein is proteolytically processed to generate multiple protein products, which may exhibit unique activities and specificities. These proteins may play a role in skin and hair morphogenesis, as well as anti-inflammatory and antimicrobial protection of mucous epithelia. Mutations in this gene may result in Netherton syndrome, a disorder characterized by ichthyosis, defective cornification, and atopy. This gene is present in a gene cluster on chromosome 5. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Oct 2015] PHENOTYPE: Homozygous mutant mice display neonatal lethality, exfoliative erythroderma, and severe dehydration. [provided by MGI curators]